package LeetCode1;

//合并二叉树
public class Num617 {
    public TreeNode mergeTrees(TreeNode root1, TreeNode root2) {
        if (root1 == null && root2 == null) {
            return null;
        }
        if (root1 != null && root2 ==  null) {
            return root1;
        }
        if (root2 != null && root1 ==  null) {
            return root2;
        }
        TreeNode cur = new TreeNode(root1.val + root2.val);
        cur.left = mergeTrees(root1.left,root2.left);
        cur.right = mergeTrees(root1.right,root2.right);
        return cur;
    }
}
